testo 425 Bedienungsanleitung Seite 2

testo 425
Large
display
Hold button
START/STOP
Battery compartment
can be unscrewed
Measuring instruments conform with
EN 50 081-1 + EN 50 082-1
With seperate velocity / temperature probe incl.
telescope (probe is connected to the
measuring instrument via a 1m cable).
If changing the length of the telescope probe the
lead is always to be directed downwards!
Please read before operation
• Never measure on live parts • Adhere to the
measuring ranges in the sensor • The data on
accuracy refers to the following adjustment con-
ditions: 1013 mbar, 22 ° C, wind tunnel with free
beam Ø 350 mm. • Overheating or flow over-
loading will destroy the probe.
• Observe the permissible storage and transport
temperature as well as the permissible operating
temperature (e.g. protect the measuring instru-
ment from direct sunlight) • Inexpert handling
or use of force make your warranty claim invalid.
Changing the settings
When switching on the instrument keep the Hold
button pressed until one of the following options
appears in the display.
The following settings can be changed:
Auto Off function: On - Off
Temperature unit: ° C - ° F
incl. the velocity unit: m/s - fpm
Change the setting via the START/ STOP button.
Press the Hold button and you will return to the
current measurement to which the changed set-
tings apply.
Instruction manual
Thermal Anemometer
Velocity in m/s
Permissible
application range
Temperature in °C
ON/OFF button Probe holder (accessories)
Technical data on testo 425
Sensor:
Hot wire, NTC
Meas. range m/s: 0 to 10 m/s or 0 to 2000 fpm
in the air with more than 20 ° C:
0 to 20 m/s or 0 to 4000 fpm
Accuracy: ±0.05 m/s ± 5% of m.v. (0 to 20 m/s)
±10 fpm ± 5% of m.v. (0 to 4000 fpm)
Meas. range °C: -20 to +70 ° C or -4 to +158 ° F
Accuracy:
±0.5 ° C (0 to 50 ° C)
±0.7 ° C (remaining range)
± 0.9 ° F (32 to 122 ° C)
±1.3 ° F (remaining range)
Resolution:
0.01 m/s (<10 m/s),
0.1 m/s (from 10 m/s)
1 fpm (<1000 fpm)
10 fpm (from 1000 fpm)
0.1 ° C - 0.1 ° F
Operating temperature: 0 to +50 °C
Storage/transport temp.: -20 to +70 °C
Housing: ABS (black) Dim.: 190x57x42 mm
Weight: Approx. 300 g Battery type: 9V block
Note: Slighty raised temperature in the case of
still air
Velocity: 0,0 m/s temperature display: +1,0°C
Velocity: 0,1 m/s temperature display: +0,4°C
Warranty:
Instr.: 2 years; probe: 1 year
Auto-Off function
If the Auto Off function is activated the
instrument automatically switches off
after 14 minutes (but not if HOLD is activated)
Changing the battery
"Bat" appears in the display when the battery life-
time remaining is approx. 30 minutes (when the
normal lifetime is 20 h, referring to an alkaline
manganese battery type). The instrument swit-
ches off automatically if the battery power is
insufficient. Unscrew the housing, remove the
used battery and put in new battery (type 9 V
block) and observe polarity.
Initital operation -
On/Off button
m/s fpm v
I _
m/s fpm
0
8 8 . . 8 8 . . 8 8 . . 8 8 °C
0 0 . . 0 0 3 3
°F
Hold Max Min Mean
BatAuto calprint
°C
cm 8 8 . . 8 8 : : . . 8 8 . . 8 8
__ 2 2 4 4 . . 2 2
°F
f t
Pull out the front part of the telescope.
When the instrument is switched on a short dis-
play and function test is carried out. The instru-
ment is then ready to operate.
Hold the probe in the air flow in accordance with
the "IN/OUT" markings.
Averaging:
Following the HOLD/MAX/MIN functions time averaging is called up via the Hold button:
m/s fpm v
Press the START/STOP button.
1 1 2 2 . . 3 3
The clock starts in the display (display in mm:ss).
Once the required measurement is complete press the START/STOP button. The duration
Hold Max Min Mean
of the measurement can be extended as often as is necessary by pressing the START -
0 0 0 0 : : 0 0 0 0
STOP button.
ST ART
m/s fpm
STOP
1 1 6 6 . . 5 5
HOLD/MAX
MIN/MEAN
ST ART
Hold Max Min
STOP
1 1 : : 2 2 5 5
Multi-point averaging is activated:
m/s fpm v
Velocity values can be saved
by pressing the START/STOP
1 1 6 6 . . 5 5
button.
Hold Max Min Mean
ST ART
STOP
0 0 0 0 0 0
Repeat the procedure as often
as required. The number of
HOLD/MAX
MIN/MEAN values saved is counted in the
display.
m/s fpm v
Call up the average value via
9 9 . . 7 7 3 3
the Hold button.
Via the Hold button you
Hold Max Min Mean
change from averaging to
0 0 5 5 4 4
current
HOLD/MAX
measurement.
MIN/MEAN
Memory function for maximum and
minimum values - Calling up aver-
aging: Hold button
v
You can jump between the following displays by
repeatedly pressing the Hold button
°C
1st press: Mixed values are fixed in the display
2nd press: Saved maximum values are displayed
3rd press: Saved minimum values are displayed
4th press: Averaging is activated
See Averaging for more details...
v m/s
Press the Hold but-
ton. The measured
1 1 4 4 . . 3 3 7 7
values are averaged
HOLD/MAX
with reference to
MIN/MEAN
Hold Max Min
Mean
time. Average and
duration are shown
on the display.
Ordering data
testo 425 measuring instrument
with separate velocity probe
(1.5 m cable) incl. battery and Instruction manual
0560.4250
9V rechargeable battery ......................0515.0025
Recharger ...........................................0554.0025
Holster (protective pocket) ..................0516.0183
Case ...................................................0516.0182
Accessory set consisting of
multi-purpose clip, (for jacket pocket,
belt and as a wall holder),
probe holder, carrier loop ....................0554.0550
fpm v
Mean
1 1 : : 2 2 5 5